Abstract: An aldose reductase inhibitor, comprising a compound of the formula (I) ##STR1## or a pharmaceutically acceptable salt thereof as the effective component, in which R is lower alkyl or cyclohexylmethyl and n is 2 or 3. The compounds of formula (I) and salts thereof according to the invention exhibit a superior aldose reductase inhibiting activity with simultaneous high stability, so that they are useful for the prevention and therapy of diabetic complications.

Abstract: An aldose reductase inhibitor, comprising a compound of the formula ##STR1## or a pharmaceutically acceptable salt thereof as the effective component, in which R denotes an alkyl of C.sub.1-12, ##STR2## wherein X.sub.1 and X.sub.2 are same or different and are hydrogen or halogen, cyclohexylmethyl, cyclohexyl, tetra-hydro-2H-pyran-1-yl-methyl, carboxy-lower alkyl or cyclo-lower alkyl and n is 2 or 3. These compounds exhibit a superior aldose reductase inhibiting activity with simultaneous high stability, and are for use in the prevention and therapy of diabetic complications.

Abstract: A antibiotic L53-18A and a pharmaceutically acceptable salt thereof which are useful for treatment of bacterial inventions are obtained by culturing, for example, Saccharopolyspora sp. L53-18 (FERM BP 2231) in a medium and the antibiotic accumulated therein is collected.

Abstract: A compound of the formula ##STR1## wherein R is .beta.-D-glucopyranosyl, .beta.-D-galactopyranosyl, 6'-O-acetyl-.beta.-D-glucopyranosy or 6'-O-acetyl-.beta.-D-galactopyranosyl, or a pharmaceutically acceptable salt thereof, has bronchodilator, cardiac activity, smooth muscle relaxant activity and hormone excretion stimulant activity. It can be produced by culturing a microorganism belonging to the genus Nodulisporium and adapted to produce the compound in a culture medium, and isolating the produced compound from the cultured medium. The microorganism can be Nodulisporium sp. M5220 FERM P-8133. The compounds have inhibitory activity on cyclic-adenosine-3',5'-monophosphate phosphodiesterase.

Abstract: A physiologically-active novel substance "aldostatin" having an estimated molecular formula of C.sub.20 H.sub.20 N.sub.2 O.sub.8 is produced by culturing an aldostatin-producing microorganism of the Pseudeurotium, for example, the Pseudeurotium zonatum M4109 strain. Aldostatin inhibits the aldose reductase activity and as a consequence, avoids abnormal accumulation of sorbitol, galactitol, etc. It is therefore effective for the treatment of chronic complications such as cataract, retinopathy and neuropathy caused by diabetes renalis.

Abstract: A substance is provided which has strong enzyme inhibitory activity against thiol proteases such as papain, ficin, bromelain, etc. and which is represented by the following formula: ##STR1## (wherein R is a hydrogen atom or a hydroxyl group), its pharmaceutically acceptable salt or hydrate.

Abstract: Neplanocin A derivatives of the formula ##STR1## wherein R.sub.1 and R.sub.2 are hydrogen or benzoyl, R.sub.3 is hydrogen or OR.sub.8, R.sub.5 is hydrogen or acetyl, R.sub.6 is hydrogen, acetyl or benzoyl, when R.sub.3 is hydrogen, R.sub.4 is hydrogen or halogen, hydroxy, acetoxy, acetylthio, amino or azide, and when R.sub.3 is OR.sub.8, R.sub.4 is hydrogen, R.sub.8 is hydrogen or acetyl, or R.sub.8 and R.sub.5 together form benzylidene, and at least one of R.sub.8, R.sub.5 and R.sub.6 is other than hydrogen. The compounds of the present invention have inhibitory action for the growth of L 5178 Y cells and have the same or superior activity as neplanocin A, and hence are useful as antitumor agents.

Abstract: Antibiotic neplanocin A of the formula ##STR1## is produced by culturing Ampullariella sp. A 11079 FERM-P No. 4494 in a nutrient medium and then separating the neplanocin A thus produced from the culture medium.

Abstract: Neplanocin-B and -F of the formula ##STR1## in which Y is oxygen or a valence bond, are produced by culturing Ampullariella sp. A 11079 FERM-P No. 4494 in a nutrient medium and then separating the neplanocin-B and -F thus produced from the culture medium.

Abstract: A group of sulfur-containing antibiotics, planothiocin-A, -B, -C, -D, -E, -F and -G, are produced by culturing Actinoplanes sp. A12526 in a nutrient medium, and separating the thus-produced planothiocins therefrom. The novel antibiotics have utility in therapeutic or prophylactic antibacterial compositions or feed additives for livestock, poultry or fish.